An interior permanent magnet machine generally includes a rotor having a plurality of magnets of alternating polarity around the outer periphery of the rotor. The rotor is rotatable within a stator which generally includes a plurality of windings and magnetic poles of alternating polarity. Permanent magnet machines may produce undesirable torque ripple, resulting in unwanted vibration and noise. Traditionally, the configuration of the rotor in interior permanent magnet machines is axially symmetric.